I'm pretty sure they are 70mm.
Not 100% positive though.
But I did have a tubular with a 70mm TB that I know I did not port (could have been, but not by me) and it was a match.
Every time we talk about gt40 intakes, I wish I still had mine even though I don't own anything it fits on.
Hey when you measure the TB to know if it’s a 65, 70 etc which side are they measuring to get that sizing? Is it at the mouth opening or at the side that connects to the intake?